Role of catalytic nitrile decomposition in tricopper complex mediated direct partial oxidation of methane to methanol

Synthetic homogeneous system known to date performing methane to methanol conversion using O2 as terminal oxidant is unique and based on copper complex with piperazine-based ligand (Cu3L in Fig. 1) in a medium of acetonitrile. Prior work have shown that in order to achieve catalytic turnover, hydrogen peroxide is needed to regenerate the active site. We show in this paper that reaction solvent based on organic nitrile decompose concurrently with methane activation and that in the absence of either acetonitrile, Cu complex or hydrogen peroxide, the catalytic turnover does not happen. We show in this manuscript that the direct methane oxidation to methanol might have been mediated by catalytic Radziszewski oxidation between acetonitrile and H2O2. Additionally we have discovered that in the absence of methane, peroxide mediated acetonitrile decomposition also makes methanol via a background reaction which was hitherto unknown.

ANNEALING OF OLIGONUCLEOTIDE HAIRPINS AS EFFECTIVE APPROACH TO IMPROVE THE ANALYTICAL CHARACTERISTICS OF AMPLIFICATION METHOD FOR MICRORNA DETERMINATION BASED ON CATALYTIC HAIRPIN ASSEMBLY REACTION

This work presents a new approach for reducing the background reaction of the catalytic hairpin assembly (CHA) amplification method, based on optimizing the conditions for annealing of hairpin oligonucleotide probes. This approach made it possible to improve the analytical characteristics of the amplified CHA-based method for microRNAs quantitation.

EFFECT OF DUAL TASK EXERCISES ON REACTION TIME IN SCHOOL BASKETBALL PLAYERS

Background: Reaction time is the time taken to respond to a stimulus. Reaction time is a pre-requisite of any sports player. A short reaction time is an indicative of swift movements and attentiveness on field of the player. A player on field should have the ability to multitask. This ability is strengthened using dual task exercises. Method: Participants- 27 school basketball players of 13-16 years were included in the study. Hand dominance was assessed using the handedness questionnaire and leg dominance was assessed by asking the participant to kick the ball. Reaction time was assessed using the reaction timer and dynamic balanced was assessed using the Y balance test. Both the parameters were recorded as a pretest and posttest after intervention of dual task exercises. As an intervention 3 dual task exercises throwing and catching a ball while walking, spot marching and jump up to reach targets and side marching and passing the ball were used. Each exercise was done for a period of 8-10 mins respectively. During this time their regular basketball practice and physical fitness exercises were continued in school respectively. Results: The data was analyzed using SPSS version 24.0. A significant change was found in the reaction time of basketball players with p Value obtained as 7.26E-06. The balance component showed a significant improvement as well. P Values obtained for Anterior direction is 0.048, for posteromedial direction is 0.053and for posterolateral direction is 0.014. Conclusion: Dual task exercises along with basketball training were effective in improving the reaction time and dynamic balance in basketball players. KEY WORDS: Reaction time, dual task exercises, Dynamic balance, Y balance test, School basketball players.

Mukaiyama Aldol Reaction Catalyzed by (Benz)imidazolium-Based Halogen Bond Donors

A series of cationic monodentate and bidentate iodo(benz)­imidazolium-based halogen bond (XB) donors were employed as catalysts in a Mukaiyama aldol reaction. While 5 mol% of a monodentate variant showed noticeable activity, a <i>syn</i>-preorganized bidentate XB donor provided a strong performance even with 0.5 mol% loading. In contrast to the very active BAr^F₄ salts, PF₆ or OTf salts were either inactive or showed background reaction. Repetition experiments clearly ruled out a potential hidden catalysis by elemental iodine and demonstrated the stability of our catalyst over three consecutive cycles.

Mukaiyama Aldol Reaction Catalyzed by (Benz)imidazolium-Based Halogen Bond Donors

A series of cationic monodentate and bidentate iodo(benz)­imidazolium-based halogen bond (XB) donors were employed as catalysts in a Mukaiyama aldol reaction. While 5 mol% of a monodentate variant showed noticeable activity, a <i>syn</i>-preorganized bidentate XB donor provided a strong performance even with 0.5 mol% loading. In contrast to the very active BAr^F₄ salts, PF₆ or OTf salts were either inactive or showed background reaction. Repetition experiments clearly ruled out a potential hidden catalysis by elemental iodine and demonstrated the stability of our catalyst over three consecutive cycles.

Multiple Myeloma 1 Transcription Factor Is Superior to CD138 as a Marker of Plasma Cells in Endometrium

Chronic endometritis is characterized by plasma cell (PC) infiltration of endometrial stroma. Identification of PCs can be challenging by routine hematoxylin and eosin (H&E) stain due to the low numbers of PCs or to their being obscured by other cells in the stroma. CD138 is widely used as an ancillary immunohistochemistry stain to identify PCs; however, it has a high background reaction. In this study, multiple myeloma 1 (MUM1) transcription factor is introduced as an alternative PC marker in endometrial tissues. In this study, 311 endometrial biopsies, submitted to rule out chronic endometritis, were selected. They were divided into Group I (n = 87) and Group II (n = 224). Both had MUM1 and H&E while Group I also had accompanying CD138 stains. In both groups combined, MUM1 detected plasma cells in 48% of the cases, while CD138 and H&E identified the cells in 23% and 15% of the biopsies, respectively. In addition to having a clean background, MUM1 is a more sensitive stain than CD138 for detection of PCs in endometrium.

Immobilization of Prunus amygdalus Hydroxynitrile Lyase on Celite

The hydroxynitrile lyase from Prunus amygdalus was immobilized on Celite R-633. The immobilized enzyme could successfully be utilized in buffer saturated MTBE and excellent conversions of benzaldehyde to R-mandelonitrile were observed. No leaching occurred. To achieve high enantioselectivities, the suppression of the undesired background reaction was essential. This could be achieved by high enzyme loadings and the tight packing of the immobilized enzymes. When the immobilized enzyme is loosely packed, both the enzyme catalysis and the background reaction accelerates and only a modest enantioselectivity is observed. The enzyme was recycled for up to ten times, with some loss of activity and also enantioselectivity after 5 cycles, independent of packing.

Assessing the Activity of Lewis Bases Organocatalysts in Halonium-Induced Carbocyclization Reactions

Lewis bases were evaluated as catalysts for halocarbocyclization reactions of alkynylstyrenes and a cinnamylaniline derivative. Phosphines and phosphorus chalcogenides exhibited high activity for the conversion of alkynylstyrenes in the presence of N-halosuccinimides with up to a 30-fold increase of the initial reaction rate with respect to the background reaction. Phosphorus sulfides and selenides showed the best catalytic activity for the iodocarbocyclization of a cinnamylaniline derivative in the presence of diiodohydantoin. An asymmetric variant of the iodocarbocyclization reaction of an alkynylstyrene using a chiral phosphorus selenide resulted in a modest enantioselectivity.

Elucidating the Role of Isotopically Chiral Initiators in the Soai Asymmetric Autocatalytic Reaction

A mechanistic rationalization is given for how asymmetric amplification is induced with fidelity in the Soai autocatalytic reaction by chiral initiators that are enantiomeric only by virtue of an isotope, e.g. – CH3 vs.CD3. A transient <i>inhibition</i> of the autocatalytic pathway at the outset of the reaction implicates an interaction between initiator and product initially formed in the uncatalyzed background reaction. Selectivity in formation of the product-initiator complex ultimately induces a slight enantioenrichment in the active dimer catalysts that trigger and direct the autocatalytic pathway.<br>

Elucidating the Role of Isotopically Chiral Initiators in the Soai Asymmetric Autocatalytic Reaction

A mechanistic rationalization is given for how asymmetric amplification is induced with fidelity in the Soai autocatalytic reaction by chiral initiators that are enantiomeric only by virtue of an isotope, e.g. – CH3 vs.CD3. A transient <i>inhibition</i> of the autocatalytic pathway at the outset of the reaction implicates an interaction between initiator and product initially formed in the uncatalyzed background reaction. Selectivity in formation of the product-initiator complex ultimately induces a slight enantioenrichment in the active dimer catalysts that trigger and direct the autocatalytic pathway.<br>